RBTR 0.56oz Membrane 7

Almost makes me want to jump back on the horse and make another quilt! Interesting they stayed with a 7d fabric. I know they were testing some 5d nylons a while back. Great time to be a MYOG’er.

PS – $19/yd a little hard to swallow.

Ryan

maybe 3 square yards in a quilt.  6 total for inner and outer fabric.  56 fabric would save 0.6 ounces compared to their 66 fabric.  If I was making a quilt I might choose the 56 fabric.

I made a quilt, vest, and hood with the 66 membrane.  They came out really good.  Fairly fragile though, good for an inside layer, maybe not so good for an outer layer that gets subjected to abuse.

maybe 3 square yards in a quilt.  6 total for inner and outer fabric.  56 fabric would save 0.6 ounces compared to their 66 fabric.

Not sure that it’s worth spending $60 to save 0.6 ounces on a down quilt. That’s $100 per ounce saved, not to mention unknown material longevity. In comparison, moving from a silnylon tent ($300) to a DCF tent ($600) can save several ounces, around $40 – $50 per ounce saved.

Anyone seen any MYOG or cottage quilts made out of this yet?

Yeah, that price is getting close to DCF territory, and not worth the extra over the .66 stuff.  For me.  It’s pretty far past the point of diminishing returns.

A few years ago I did a weight-saved vs cost survey.

Pick any item of gear and find the cheapest option that meets your feature/quality needs.  Then find lighter options compare the price.

I arrived a the range of $6 – $12 extra for every ounce saved ($100 – $200 per pound).  This worked for just about everything with the exception of sleeping bags (likely due to the cost of higher fill powers).  Cuben / DCF is way off the top of the chart.  As noted, so is Membrane 7.

It’s easy to spend $20 on a yard for a small project, but then the weight savings will be so small as to be irrelevant.

I bought a couple yards of the stuff on sale when it first came out. Used it in a MYOG bivy. Very nice fabric, seems like it is more breathable than their Membrane 10.

I might use it in a MYOG quilt, going with 5 yards in all black (if they ever stock it again). My logic is that if I’m spending the time to design, sew, and stuff my own quilt, then I might as well make it unique and the lightest I can. I do really like their Membrane 10 fabric though, so I might just go with it as a “known good” choice.

It appears that all of RBTR’s sub one oz breathable nylons are calendered, meaning that one side of the fabric is run over a hot roller, melting the fibers to a shiny finish on that side.  The concern is that the melting may reduce the vapor permeability of the material, a problem for a sleeping bag or quilt that needs to breath to keep you dry, regardless of whether the calendered side is on the inside.

Several years ago, a BPL member who is now in the gear business sponsored a joint purchase of a .66 oz fabric that was not calendered.  About half of it was repurchased by another member, but still have the other half, and that would be my choice for a bag or quilt.  Just enough left for that.

I don’t think a lightweight non-calendered fabric would work well for a down quilt. Too much down loss. Membrane 10 works well for me in my quilt – no issues.

A non-calendered light fabric would be nice for a synthetic quilt though.

Several years ago, a BPL member who is now in the gear business sponsored a joint purchase of a .66 oz fabric that was not calendered. About half of it was repurchased by another member, but still have the other half, and that would be my choice for a bag or quilt. Just enough left for that.

So, are you going to share it? :)

Seems like 0.56 Membrane is out of stock. Anyone know of some alternatives in the weight range? I’m thinking for uber light synthetic quilt for a specific purpose; doesn’t need to be downproof.

That a fabric is not calendered does not necessarily mean it is not downproof.  Their are various coatings, some to add DWR, that will do so.  At one time, very thin PU coatings were used on light nylon to add DWR.  But agree one has to be sure before buying for a down app.

My wife just finished two quilts made from 0.56oz Membrane 7 with synthetic insulation. I found the the material easy to rip in the direction parallel to the selvage. This was true of all 3 colors. My wife found it quite a bit more difficult to sew compared to older, somewhat heavier materials. I would have preferred something heavier and stronger. If you are easy on your gear, have a walking-foot sewing machine and want the ultimate in light weight, then give it a try. Otherwise, you might consider something more durable and easier to work with.

I concur with Robert and his Wife’s opinion on this fabric in that it is crazy light and only for those who are gentle with their gear. I would maybe be concerned sleeping in a m7 quilt/bag without socks if it had been some time since my last toe nail cutting…

I do prefer the hand feel and softness of .56m to .66m, though! I find both similar enough to work with.

Father cut your toenails, you’re tearing mother’s nightie’
British comedy.

Cheers
PS: many variants

My son’s sleeping quilt ripped the second  night of our recent trip. The next morning we found a 13.3 inch tear. He had no sensation of it ripping and is a sound sleeper and careful with his gear. The rip didn’t begin on a stitch or quilting tie although there were two smaller tears nearby that did. The fabric rips easily parallel to the selvage and doesn’t deserve the name ripstop. The reinforcing grid looks symmetrical but does little good in one direction. It is extremely difficult to sandwich this fabric with synthetic insulation even with a walking foot sewing machine operated by a very experienced seamstress. Don’t waste your time or money on it for a sleeping quilt.

but this fabric is only slighter lighter than the 0.66 oz membrane fabric.  It would only save significant weight on a large item like a quilt

If it’s not strong enough for a quilt, then there are possibly no applications where it would be useful

There are probably some people that are able to use this fabric successfully though.  And, it’s a good experiment to find the limit of how light can you go.

I just got some of the 0.66 oz fabric for some insulated pants and jacket

In respect to durability of this membrane 7…im not really sure yet. Especially after the last comment. I’ve made a few items with my concerns, but have yet to get some good use out of it. I had a a tear in one of my never-used m7 quilts from removing it from a stuff sack (due to long fingernails, damnit). This tear started right below and perpendicular to a line of sewing baffle material. The tear parallels the selvedge. This is the exact observation as Robert has described above. This is very important “data” here as not very many people have commented on durability of 7-denier fabrics being used. This one, and perhaps another offered from Dutch, seem to both be used from some smaller companies…

Membrane10 is a different story. I have 100% full confidence in this fabric (for quilts) as I used this fabric for my second ever down quilt. Over the years, it has lasted through hikes of the LT, the Cohos Trail, CDT, 1200 miles of pct/at/LT, a couple washes, and long toe nails!